Silent error when using hashmap

[FatalCatharsis via Digitalmars-d]

On Thursday, 27 July 2017 at 00:34:28 UTC, ketmar wrote:
> wrap the whole event handler function in `try/catch` block, and 
> print it there. after all, this is what Dmain does, and so can 
> you. having *full* stack trace has no sense there anyway, as 
> you know for sure that event handler is called by windows, not 
> by you (and usually from your event loop anyway, so detailed 
> stack trace has little useful info).

I tried that like so:

https://gist.github.com/FatalCatharsis/39c5f35ae78ecd5399eebe0fb2491004

I put exception blocks both around main and around the invocation 
of the hash lookup and still get no printouts anywhere, including 
at the beginning and end of main.